A semiconductor device having electronic parts, such as semiconductor elements, mounted therein is required to, for example, endure the heat cycle caused by repetitive occurrence of a hot portion and a low-temperature portion, sustain electrical connection and electrical insulation, and stably support parts. Particularly, it is important that semiconductor devices which deal with high power, including a semiconductor module having a semiconductor element for power (power semiconductor element), such as an IGBT (Insulated Gate Bipolar Transistor), should endure a high heat discharge characteristic and a repetitive heat cycle. When a crack occurs at the solder or the like of the connected portion of a power semiconductor element due to the repetitive heat cycle, the heat resistance and electrical resistance increase. When the deterioration becomes greater, heat-originated breaking may progress acceleratingly, so that the performance of the device is unlikely to be exercised.
Unexamined Japanese Patent Application KOKAI Publication No. 2006-237429 discloses a semiconductor device which has an electrode member and a semiconductor element to be mounted therein using the electrode member. The electrode member includes an insulative support plate (power feeding plate) having a plurality of through holes, and a plurality of conductive posts (power feeding posts) placed in each through hole. The conductive posts are connected to the electrodes of the semiconductor element. According to the technique disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 2006-237429, as the semiconductor element is connected using the electrode member which has a plurality of electrodes provided at a single electrode, thermal stress applied to the interface between the metallic post and the semiconductor element is likely to become smaller as compared with the case where a single conductive post is used for a single electrode. Even if the difference in the coefficient of thermal expansion between the metallic post and the semiconductor element is large, therefore, the reliability of connection of the semiconductor element can be enhanced.
Unexamined Japanese Patent Application KOKAI Publication No. 2009-64908 discloses a semiconductor device which has a support plate (power feeding plate) including, for example, a glass epoxy resin substrate, and columnar conductive posts (power feeding posts). The technique disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 2009-64908 improves the reliability of the electrical conductivity and the heat cycle durability relating to the heat conductivity.
The disclosures of Unexamined Japanese Patent Application KOKAI Publication No. 2006-237429 and Unexamined Japanese Patent Application KOKAI Publication No. 2009-64908 are incorporated by reference herein.